640004242 has 8 divisors (see below), whose sum is σ = 960315696. Its totient is φ = 319899012.

The previous prime is 640004231. The next prime is 640004257. The reversal of 640004242 is 242400046.

It is a sphenic number, since it is the product of 3 distinct primes.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 43548 + ... + 56359.

It is an arithmetic number, because the mean of its divisors is an integer number (120039462).

Almost surely, 2^640004242 is an apocalyptic number.

640004242 is a deficient number, since it is larger than the sum of its proper divisors (320311454).

640004242 is a wasteful number, since it uses less digits than its factorization.

640004242 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 103112.

The product of its (nonzero) digits is 1536, while the sum is 22.

The square root of 640004242 is about 25298.3051210946. The cubic root of 640004242 is about 861.7757799902.

Adding to 640004242 its reverse (242400046), we get a palindrome (882404288).

The spelling of 640004242 in words is "six hundred forty million, four thousand, two hundred forty-two".